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Saito T, Konno T, Hosokawa T, Asada A, Ishiguro K, Hisanaga SI. p25/cyclin-dependent kinase 5 promotes the progression of cell death in nucleus of endoplasmic reticulum-stressed neurons. J Neurochem 2007; 102:133-40. [PMID: 17506859 DOI: 10.1111/j.1471-4159.2007.04540.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dysregulation of cyclin-dependent kinase 5 (Cdk5) by cleavage of its activator p35 to p25 by calpain is involved in the neuronal cell death observed in neurodegenerative disorders, including Alzheimer's disease. However, it is not yet clear how p25/Cdk5 induces cell death, although its cytosolic localization or extended half life are thought to be involved. We show here that endoplasmic reticulum (ER) stress causes the calpain-dependent cleavage of p35 to p25 in primary cultured cortical neurons. Generation of p25 occurred at a cell death execution step in ER-stressed neurons. p25 translocated to the nucleus in ER-stressed neurons, whereas p35/Cdk5 was perinuclear in control neurons. Cdk5 inhibitors or dominant-negative Cdk5 suppressed ER stress-induced neuronal cell death. These findings indicate that p25/Cdk5 is a proapoptotic factor that promotes ER stress-induced neuronal cell death in nuclei.
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Paul S, Olausson P, Venkitaramani DV, Ruchkina I, Moran TD, Tronson N, Mills E, Hakim S, Salter MW, Taylor JR, Lombroso PJ. The striatal-enriched protein tyrosine phosphatase gates long-term potentiation and fear memory in the lateral amygdala. Biol Psychiatry 2007; 61:1049-61. [PMID: 17081505 PMCID: PMC1853327 DOI: 10.1016/j.biopsych.2006.08.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Revised: 08/01/2006] [Accepted: 08/02/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Formation of long-term memories is critically dependent on extracellular-regulated kinase (ERK) signaling. Activation of the ERK pathway by the sequential recruitment of mitogen-activated protein kinases is well understood. In contrast, the proteins that inactivate this pathway are not as well characterized. METHODS Here we tested the hypothesis that the brain-specific striatal-enriched protein tyrosine phosphatase (STEP) plays a key role in neuroplasticity and fear memory formation by its ability to regulate ERK1/2 activation. RESULTS STEP co-localizes with the ERKs within neurons of the lateral amygdala. A substrate-trapping STEP protein binds to the ERKs and prevents their nuclear translocation after glutamate stimulation in primary cell cultures. Administration of TAT-STEP into the lateral amygdala (LA) disrupts long-term potentiation (LTP) and selectively disrupts fear memory consolidation. Fear conditioning induces a biphasic activation of ERK1/2 in the LA with an initial activation within 5 minutes of training, a return to baseline levels by 15 minutes, and an increase again at 1 hour. In addition, fear conditioning results in the de novo translation of STEP. Inhibitors of ERK1/2 activation or of protein translation block the synthesis of STEP within the LA after fear conditioning. CONCLUSIONS Together, these data imply a role for STEP in experience-dependent plasticity and suggest that STEP modulates the activation of ERK1/2 during amygdala-dependent memory formation. The regulation of emotional memory by modulating STEP activity may represent a target for the treatment of psychiatric disorders such as posttraumatic stress disorder (PTSD), panic, and anxiety disorders.
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Robinson HM, Harrison CJ, Moorman AV, Chudoba I, Strefford JC. Intrachromosomal amplification of chromosome 21 (iAMP21) may arise from a breakage-fusion-bridge cycle. Genes Chromosomes Cancer 2007; 46:318-26. [PMID: 17243167 DOI: 10.1002/gcc.20412] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Intrachromosomal amplification of chromosome 21 (iAMP21), involving amplification of the RUNX1 gene and duplication of chromosome 21, dup(21q), defines a new cytogenetic subgroup in B-lineage acute lymphoblastic leukemia (ALL) with a poor prognosis. Characterization of this abnormality has become vital to ensure that the most accurate detection method is used. We have previously defined common regions of amplification and deletion of chromosome 21 in these patients, although the level and extent of amplification within the amplicon was highly variable. This study, using interphase fluorescence in situ hybridization (FISH) with chromosome 21 locus specific probes, substantiated these findings in a large series of patients and confirmed that the amplicon always included RUNX1. Thus, FISH with probes directed to the RUNX1 gene remains the most reliable detection method. Metaphase FISH, supported by G- and multiple color chromosomal banding (mBAND) revealed the patient specific morphology and genetic profile of the dup(21q) chromosomes, as well as the complexity of the intrachromosomal changes giving rise to them. These findings suggested that iAMP21 had arisen from a breakage-fusion-bridge cycle: a mechanism previously described in tumors, which we report for the first time in ALL.
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Zhang Z, Yang X, Zhang S, Ma X, Kong J. BNIP3 upregulation and EndoG translocation in delayed neuronal death in stroke and in hypoxia. Stroke 2007; 38:1606-13. [PMID: 17379825 DOI: 10.1161/strokeaha.106.475129] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Delayed neuronal death is a hallmark feature of stroke and the primary target of neuroprotective strategies. Caspase-independent apoptosis pathways are suggested as a mechanism for the delayed neuronal injury. Here we test the hypothesis that one of the caspase-independent apoptosis pathways is activated by BNIP3 and mediated by EndoG. METHODS We performed immunohistochemistry, Western blotting, cell transfection, subcellular fractionation, and RNA interfering to analyze the expression and localization of BNIP3 and EndoG in degenerating neurons in models of stroke and hypoxia. RESULTS BNIP3 was upregulated in brain neurons in a rat model of stroke and in cultured primary neurons exposed to hypoxia. The expressed BNIP3 was localized to mitochondria. Both forced expression of BNIP3 by plasmid transfection and induced expression of BNIP3 by hypoxia in neurons resulted in mitochondrial release and nuclear translocation of EndoG and neuronal cell death. Knockdown of BNIP3 by RNAi inhibited EndoG translocation and protected against hypoxia-induced neuronal death. CONCLUSIONS BNIP3 plays a role in delayed neuronal death in hypoxia and stroke and EndoG is a mediator of the BNIP3-activated neuronal death pathway. The results suggest that BNIP3 may be a new target for neuronal rescue strategies.
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Harant H, Wolff B, Schreiner EP, Oberhauser B, Hofer L, Lettner N, Maier S, de Vries JE, Lindley IJ. Inhibition of Vascular Endothelial Growth Factor Cotranslational Translocation by the Cyclopeptolide CAM741. Mol Pharmacol 2007; 71:1657-65. [PMID: 17369307 DOI: 10.1124/mol.107.034249] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The cyclopeptolide CAM741 inhibits cotranslational translocation of vascular cell adhesion molecule 1 (VCAM1), which is dependent on its signal peptide. We now describe the identification of the signal peptide of vascular endothelial growth factor (VEGF) as the second target of CAM741. The mechanism by which the compound inhibits translocation of VEGF is very similar or identical to that of VCAM1, although the signal peptides share no obvious sequence similarities. By mutagenesis of the VEGF signal peptide, two important regions, located in the N-terminal and hydrophobic segments, were identified as critical for compound sensitivity. CAM741 alters positioning of the VEGF signal peptide at the translocon, and increasing hydrophobicity in the h-region reduces compound sensitivity and causes a different, possibly more efficient, interaction with the translocon. Although CAM741 is effective against translocation of both VEGF and VCAM1, the derivative NFI028 is able to inhibit only VCAM1, suggesting that chemical derivatization can alter not only potency, but also the specificity of the compounds.
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Jia J, Wang X, Li H, Han S, Zu P, Li J. Activations of nPKCε and ERK1/2 Were Involved in Oxygen-Glucose Deprivation-induced Neuroprotection via NMDA Receptors in Hippocampal Slices of Mice. J Neurosurg Anesthesiol 2007; 19:18-24. [PMID: 17198096 DOI: 10.1097/01.ana.0000211020.88431.e2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Accumulated reports have suggested that activation of protein kinase C (PKC) isoforms may involve the activation of extracellular signal-regulated kinases (ERKs) in the neuronal response to ischemic/hypoxic stimuli. We have previously demonstrated that the membrane translocation of novel PKC (nPKC) epsilon increased in the early phase of cerebral ischemic/hypoxic preconditioning of mice. In this study, we used Western blot analysis and propidium iodide stain to determine whether the activations of nPKCepsilon and ERKs were involved in oxygen-glucose deprivation (OGD)-induced neuroprotection via N-methyl-D-aspartate (NMDA) receptors. The hippocampal slices of mice were exposed to OGD for 10 (OGD10) or 45 minutes (OGD45) to mimic mild (causing ischemic/hypoxic preconditioning) and severe (causing severe OGD) ischemia/hypoxia, respectively. We found that OGD10-induced nPKCepslilon membrane translocation was mediated by NMDA receptors, and both OGD10 and NMDA (1 microM, 30 min) pretreatment could protect Cornu Ammonis region 1 neurons against the subsequent severe OGD45. In addition, nPKCepsilon translocation inhibitor, epsilonV1-2 (1 microM, 30 min), and ERKs upstream mitogen-activated protein/extracellular signal regulated kinase kinase inhibitor, PD-98059 (20 microM, 30 min), could significantly inhibit OGD10 and NMDA-induced neuroprotection. These results suggest that OGD10-induced neuroprotection against severe OGD45 in the Cornu Ammonis region 1 region of the hippocampal slices was mediated by the activations of NMDA receptors, nPKCepsilon, and the downstream ERKs.
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Soberanes S, Panduri V, Mutlu GM, Ghio A, Bundinger GRS, Kamp DW. p53 mediates particulate matter-induced alveolar epithelial cell mitochondria-regulated apoptosis. Am J Respir Crit Care Med 2006; 174:1229-38. [PMID: 16946128 PMCID: PMC2648105 DOI: 10.1164/rccm.200602-203oc] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 08/31/2006] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Exposure to particulate matter (PM) causes lung cancer by mechanisms that are unknown, but p53 dysfunction is implicated. OBJECTIVE We determined whether p53 is required for PM-induced apoptosis in both human and rodent alveolar type (AT) 2 cells. METHODS A well-characterized form of urban PM was used to determine whether it induces mitochondrial dysfunction (mitochondrial membrane potential change [DeltaPsi m] and caspase-9 activation), p53 protein and mRNA expression, and apoptosis (DNA fragmentation and annexin V staining) in vitro using A549 cells and primary isolated human and rat AT2 cells. The role of p53 was assessed using inhibitors of p53-dependent transcription, pifithrin-alpha, and a genetic approach (overexpressing E6 or dominant negative p53). In mice, the in vivo effects of PM causing p53 expression and apoptosis were assessed 72 h after a single PM intratracheal instillation. MEASUREMENTS AND MAIN RESULTS PM-induced apoptosis in A549 cells was characterized by increased p53 mRNA and protein expression, mitochondrial translocation of Bax and p53, a reduction in DeltaPsi m, and caspase-9 activation, and these effects were blocked by inhibiting p53-dependent transcription. Similar findings were noted in primary isolated human and rat AT2 cells. A549-rho degrees cells that are incapable of mitochondrial reactive oxygen species production were protected against PM-induced DeltaPsi m, p53 expression, and apoptosis. In mice, PM induced p53 expression and apoptosis at the bronchoalveolar duct junctions. CONCLUSIONS These data suggest a novel interaction between p53 and the mitochondria in mediating PM-induced apoptosis that is relevant to the pathogenesis of lung cancer from air pollution.
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Fujii T, Tanaka N, Yokoyama T, Ninaki O, Oshiki T, Ohnuma A, Tazima Y, Banno Y, Ajimura M, Mita K, Seki M, Ohbayashi F, Shimada T, Abe H. The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes. Genetica 2006; 127:253-65. [PMID: 16850229 DOI: 10.1007/s10709-005-4147-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 10/17/2005] [Indexed: 10/24/2022]
Abstract
Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ( Sa ) + ( p )W + ( od ))Fem, derived from the translocation-carrying W chromosome (p ( Sa ) + ( p )W + ( od )), is inert as femaleness determinant. Moreover, this Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome are produced. Initially, to investigate whether the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is viable. Therefore, we concluded that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ( Sa ) + ( p )W + ( od ).
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Laumonnier F, Roger S, Guérin P, Molinari F, M'rad R, Cahard D, Belhadj A, Halayem M, Persico AM, Elia M, Romano V, Holbert S, Andres C, Chaabouni H, Colleaux L, Constant J, Le Guennec JY, Briault S. Association of a functional deficit of the BKCa channel, a synaptic regulator of neuronal excitability, with autism and mental retardation. Am J Psychiatry 2006; 163:1622-9. [PMID: 16946189 DOI: 10.1176/ajp.2006.163.9.1622] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Autism is a complex, largely genetic psychiatric disorder. In the majority of cases, the cause of autism is not known, but there is strong evidence for a genetic etiology. To identify candidate genes, the physical mapping of balanced chromosomal aberrations is a powerful strategy, since several genes have been characterized in numerous disorders. In this study, the authors analyzed a balanced reciprocal translocation arising de novo in a subject with autism and mental retardation. METHOD The authors performed the physical mapping of the balanced 9q23/10q22 translocation by fluorescent in situ hybridization experiments using bacterial artificial chromosome clones covering the areas of interest. RESULTS Findings revealed that the KCNMA1 gene, which encodes the alpha-subunit of the large conductance Ca(2+)-activated K(+) (BK(Ca)) channel, a synaptic regulator of neuronal excitability, is physically disrupted. Further molecular and functional analyses showed the haploinsufficiency of this gene as well as decreased activity of the coded BK(Ca )channel. This activity can be enhanced in vitro by addition of a BK(Ca )channel opener (BMS-204352). Further mutational analyses on 116 autistic subjects led to the identification of an amino acid substitution located in a highly conserved domain of the protein not found in comparison subjects. CONCLUSIONS These results suggest a possible association between a functional defect of the BK(Ca) channel and autistic disorder and raise the hypothesis that deficits in synaptic transmission may contribute to the physiopathology of autism and mental deficiency.
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MESH Headings
- Autistic Disorder/genetics
- Autistic Disorder/physiopathology
- Child
- Chromosome Aberrations
- Chromosome Mapping
- Chromosomes, Artificial, Bacterial/genetics
- Chromosomes, Artificial, Bacterial/physiology
- Chromosomes, Human, Pair 10/genetics
- Chromosomes, Human, Pair 9/genetics
- Cloning, Molecular/methods
- DNA Mutational Analysis
- Humans
- In Situ Hybridization, Fluorescence
- Indoles/pharmacology
- Intellectual Disability/genetics
- Intellectual Disability/physiopathology
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/drug effects
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/genetics
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/physiology
- Male
- Reverse Transcriptase Polymerase Chain Reaction
- Synaptic Transmission/drug effects
- Synaptic Transmission/genetics
- Synaptic Transmission/physiology
- Translocation, Genetic/genetics
- Translocation, Genetic/physiology
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Wickham CL, Harries LW, Sarsfield P, Joyner MV, Ellard S. Large variation in t(11;14)(q13;q32) and t(14;18)(q32;q21) translocation product size is confirmed by sequence analysis of PCR products. ACTA ACUST UNITED AC 2006; 28:248-53. [PMID: 16898964 DOI: 10.1111/j.1365-2257.2006.00790.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Polymerase chain reaction is commonly used to detect t(11;14)(q13;q32) and t(14;18)(q32;q21) chromosomal translocations associated with mantle cell lymphoma and follicular lymphoma. We tested a total of 482 samples from patients with suspected non-Hodgkin's lymphoma and sequenced unusual-sized t(11;14)(q13;q32) and t(14;18)(q32;q21) products from 33 of these patients. BCL-1 or BCL-2 gene rearrangements were confirmed in 23 of 33 patients (70%). Considerable size variation was observed using t(11;14) primers, with MTCA and MTCB t(11;14) products ranging from 234 to 934 bp and 143 to 560 bp respectively. Less variability was observed for t(14;18) Major Breakpoint Region (MBR) products (100-252 bp) but Minor Cluster Region (MCR) products ranged from 217 to 498 bp. We demonstrate the utility of sequence analysis to confirm unusual-sized translocation products and reduce false-positive results because of nonspecific amplification.
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MESH Headings
- Chromosomes, Human, Pair 11/genetics
- Chromosomes, Human, Pair 14/genetics
- Chromosomes, Human, Pair 18/genetics
- Genes, bcl-1/genetics
- Genes, bcl-2/genetics
- Humans
- Lymphoma, Non-Hodgkin/genetics
- Molecular Sequence Data
- Polymerase Chain Reaction
- Retrospective Studies
- Translocation, Genetic/genetics
- Translocation, Genetic/physiology
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Ahmad N, Wang Y, Haider KH, Wang B, Pasha Z, Uzun O, Ashraf M. Cardiac protection by mitoKATP channels is dependent on Akt translocation from cytosol to mitochondria during late preconditioning. Am J Physiol Heart Circ Physiol 2006; 290:H2402-8. [PMID: 16687609 DOI: 10.1152/ajpheart.00737.2005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This investigation elucidates the Akt/mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channel signaling pathway in late pharmacological preconditioning, using the mitoK(ATP) channel openers BMS-191095 (BMS) and diazoxide (DE). BMS (1 mg/kg ip) and DE (7 mg/kg ip) alone or BMS plus wortmannin (WTN, 15 microg/kg ip), an inhibitor of phosphatidylinositol 3-kinase, and BMS plus 5-hydroxydecanoic acid (5-HD, 5 mg/kg ip), an inhibitor of mitoK(ATP) channels, were administered to male mice. Twenty-four hours later, hearts were isolated and subjected to 40 min of ischemia and 120 min of reperfusion via Langendorff's apparatus. Both BMS and DE reduced left ventricular end-diastolic pressure and increased left ventricular developed pressure as well as reduced LDH release. Coadministration of BMS and WTN abolished the beneficial effects of BMS on cardiac function. Moreover, BMS and DE accelerated Akt phosphorylation in cardiac tissue as determined by Western blot analysis and also significantly reduced apoptosis compared with ischemic control. WTN significantly suppressed BMS-induced Akt phosphorylation, whereas 5-HD had no effect on Akt phosphorylation in cytosol, and the effect of BMS on apoptosis was abolished. It is concluded that the cardioprotective effect by mitoK(ATP) channels is attributed to the translocation of phosphorylated Akt from cytosol to mitochondria.
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Branco MR, Pombo A. Intermingling of chromosome territories in interphase suggests role in translocations and transcription-dependent associations. PLoS Biol 2006; 4:e138. [PMID: 16623600 PMCID: PMC1440941 DOI: 10.1371/journal.pbio.0040138] [Citation(s) in RCA: 496] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 02/27/2006] [Indexed: 01/27/2023] Open
Abstract
After mitosis, mammalian chromosomes partially decondense to occupy distinct territories in the cell nucleus. Current models propose that territories are separated by an interchromatin domain, rich in soluble nuclear machinery, where only rare interchromosomal interactions can occur via extended chromatin loops. In contrast, recent evidence for chromatin mobility and high frequency of chromosome translocations are consistent with significant levels of chromosome intermingling, with important consequences for genome function and stability. Here we use a novel high-resolution in situ hybridization procedure that preserves chromatin nanostructure to show that chromosome territories intermingle significantly in the nucleus of human cells. The degree of intermingling between specific chromosome pairs in human lymphocytes correlates with the frequency of chromosome translocations in the same cell type, implying that double-strand breaks formed within areas of intermingling are more likely to participate in interchromosomal rearrangements. The presence of transcription factories in regions of intermingling and the effect of transcription impairment on the interactions between chromosomes shows that transcription-dependent interchromosomal associations shape chromosome organization in mammalian cells. These findings suggest that local chromatin conformation and gene transcription influence the extent with which chromosomes interact and affect their overall properties, with direct consequences for cell-type specific genome stability. The authors apply a novel high-resolution in situ hybridization method that preserves chromatin nanostructure and show that chromosome territories intermingle significantly in the nucleus of human cells.
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Golay J, Cortiana C, Manganini M, Cazzaniga G, Salvi A, Spinelli O, Bassan R, Barbui T, Biondi A, Rambaldi A, Introna M. The sensitivity of acute lymphoblastic leukemia cells carrying the t(12;21) translocation to campath-1H-mediated cell lysis. Haematologica 2006; 91:322-30. [PMID: 16531255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Campath-1H is used in conditioning regimens and more recently as an anti-leukemic therapy in acute lymphoblastic leukemias (ALL). We therefore investigated CD52 expression and campath-1H-mediated lysis of ALL cells in vitro. DESIGN AND METHODS Complement-mediated cytotoxicity assays were performed on freshly isolated neoplastic cells and cell lines using human serum. Antibody-dependent cellular cytotoxicity (ADCC) was performed by calcein-AM release assays. RESULTS CD52 was expressed in four out of eight ALL cell lines studied. Among 61 freshly isolated ALL samples CD52 was expressed at varying levels in 87% of cases. Whereas ADCC was equivalent in different CD52+ lines, complement-dependent cytotoxicity (CDC) was variable. The REH cell line bearing the t(12;21) translocation showed 47-60% lysis when treated with 10 microg/mL campath-1H compared to 0-6% for the other cell lines expressing equivalent amounts of CD52. Furthermore all nine ALL samples with t(12;21) showed very high CDC (mean 97%) compared to the other 24 CD52+cases (mean 24%)(p<0.0001). In t(12;21) samples, efficient CDC was obtained with as little as 1 microg/mL campath-1H. CDC correlated in part with CD52 levels, suggesting that CD52 expression and other yet undefined factors contribute to the particular sensitivity of t(12;21) cells. The resistance of non t(12;21) ALL cases could be overcome to a limited extent by increasing the concentration of campath-1H, blocking the CD55 and CD59 complement inhibitors, and more effectively by combining campath-1H with fludarabine. INTERPRETATION AND CONCLUSIONS We conclude that most ALL samples express CD52 to a variable level and that campath-1H has cytotoxic activity against CD52+ALL, alone or in combination with cytotoxic drugs.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Alemtuzumab
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal, Humanized
- Antibodies, Neoplasm/pharmacology
- Cell Death/drug effects
- Cell Death/physiology
- Cell Line, Tumor
- Child
- Child, Preschool
- Dose-Response Relationship, Drug
- Humans
- Middle Aged
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Translocation, Genetic/drug effects
- Translocation, Genetic/physiology
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Nam CH, Rabbitts TH. The role of LMO2 in development and in T cell leukemia after chromosomal translocation or retroviral insertion. Mol Ther 2005; 13:15-25. [PMID: 16260184 DOI: 10.1016/j.ymthe.2005.09.010] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 09/21/2005] [Accepted: 09/21/2005] [Indexed: 01/23/2023] Open
Abstract
Chromosomal translocations are primary events in the development of leukemias, representing at least one genetic feature of the putative cancer stem cell. Studies of genes influenced by chromosomal translocations have yielded a vast amount of information about how cancer is initiated and maintained. In particular, acute leukemias have demonstrated that chromosomal translocations often involve transcription regulators that function by interacting with proteins and by controlling cell fate in the aberrant setting of the developing cancer cell. As a quintessential chromosomal translocation gene product, LMO2 has many properties that typify this class of molecule. In addition to its involvement in chromosomal translocations, the LMO2 gene was inadvertently activated in an X-SCID gene therapy trial by retroviral insertion. New molecular therapies targeted directly at the LMO2 protein could have major impact as adjuncts to existing therapies or as therapeutics in their own right. In this review, we outline the current knowledge about LMO2 and some possible routes to develop reagents that might be possible macromolecular drugs in the future.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Endothelium, Vascular/physiology
- Genetic Therapy
- Hematopoiesis
- Humans
- LIM Domain Proteins
- Leukemia, T-Cell/genetics
- Leukemia, T-Cell/metabolism
- Metalloproteins/genetics
- Metalloproteins/physiology
- Mice
- Mice, Transgenic
- Multiprotein Complexes/physiology
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/metabolism
- Proto-Oncogene Proteins
- Retroviridae/genetics
- Transcription, Genetic
- Translocation, Genetic/genetics
- Translocation, Genetic/physiology
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Drynan LF, Pannell R, Forster A, Chan NMM, Cano F, Daser A, Rabbitts TH. Mll fusions generated by Cre-loxP-mediated de novo translocations can induce lineage reassignment in tumorigenesis. EMBO J 2005; 24:3136-46. [PMID: 16096649 PMCID: PMC1201345 DOI: 10.1038/sj.emboj.7600760] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 07/08/2005] [Indexed: 11/09/2022] Open
Abstract
Chromosomal translocations are primary events in tumorigenesis. Those involving the mixed lineage leukaemia (MLL) gene are found in various guises and it is unclear whether MLL fusions can affect haematopoietic differentiation. We have used a model in which chromosomal translocations are generated in mice de novo by Cre-loxP-mediated recombination (translocator mice) to compare the functionally relevant haematopoietic cell contexts for Mll fusions, namely pluripotent stem cells, semicommitted progenitors or committed cells. Translocations between Mll and Enl or Af9 cause myeloid neoplasias, initiating in pluripotent stem cells or multipotent myeloid progenitors. However, while Mll-Enl translocations can also cause leukaemia from T-cell progenitors, no tumours arose with Mll-Af9 translocations in the T-cell compartment. Furthermore, Mll-Enl translocations in T-cell progenitors can cause lineage reassignment into myeloid tumours. Therefore, a permissive cellular environment is required for oncogenicity of Mll-associated translocations and Mll fusions can influence haematopoietic lineage commitment.
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MESH Headings
- Animals
- Bone Marrow Cells/metabolism
- Bone Marrow Cells/pathology
- Cell Lineage/physiology
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cells, Cultured
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Histone-Lysine N-Methyltransferase
- Integrases/genetics
- Integrases/metabolism
- Leukemia, Lymphoid/metabolism
- Leukemia, Lymphoid/pathology
- Leukemia, Myeloid/metabolism
- Leukemia, Myeloid/pathology
- Mice
- Multipotent Stem Cells/metabolism
- Multipotent Stem Cells/pathology
- Myeloid Progenitor Cells/metabolism
- Myeloid Progenitor Cells/pathology
- Myeloid-Lymphoid Leukemia Protein
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Pluripotent Stem Cells/metabolism
- Pluripotent Stem Cells/pathology
- Proto-Oncogenes/genetics
- Recombination, Genetic
- T-Lymphocytes/metabolism
- T-Lymphocytes/pathology
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Translocation, Genetic/genetics
- Translocation, Genetic/physiology
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Sheppard FR, Moore EE, McLaughlin N, Kelher M, Johnson JL, Silliman CC. Clinically relevant osmolar stress inhibits priming-induced PMN NADPH oxidase subunit translocation. ACTA ACUST UNITED AC 2005; 58:752-7; discussion 757. [PMID: 15824651 DOI: 10.1097/01.ta.0000159246.33364.72] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The plasma membrane NADPH oxidase is responsible for the external generation of superoxide by neutrophils (polymorphonucleocytes [PMNs]). The oxidase is a multicomponent enzyme, active only when all subunits are translocated to and assembled at the membrane. We have recently demonstrated that platelet-activating factor (PAF) priming of PMNs translocates the cytosolic p67 subunit to the membrane position. Osmolar stress attenuates PAF priming of the oxidase. Consequently, we hypothesized that clinically relevant osmolar stress inhibits PAF priming-induced p67 translocation. METHODS Isolated human PMNs were incubated at 37 degrees C for 5 minutes in buffer or 180 mmol/L hypertonic saline (HTS) followed by 3 minutes of incubation with or without 2 mumol/L PAF (resting, PAF, HTS, and HTS-PAF). Digital microscopy was used to determine p67 location in whole PMNs. Subcellular fractions were prepared and membrane translocation of p67 determined by protein electrophoresis. Resting cytosol fractions were immunodepleted of p67 and NADPH oxidase activity measured using p67-deficient sodium dodecyl sulfate cell-free oxidase assays: resting, PAF, or HTS-PAF membrane (1 mug) was combined with immunodepleted resting cytosol (25 mug). RESULTS By all methodologies, PAF stimulated translocation of p67 to the PMN membrane and this translocation was prevented by osmolar stress (HTS-PAF). In cell-free oxidase assays, the membrane content of p67 after PAF stimulation was increased sufficiently to induce oxidase activity, whereas resting and HTS-PAF membrane did not (0.1 +/- 0.02, 0.23 +/- 0.04, and 0.14 +/- 0.04, respectively, p < 0.01) (resting versus HTS-PAF, no difference). CONCLUSION PAF priming of the PMN oxidase involves translocation of p67 to the plasma membrane. Clinically relevant osmolar stress with hypertonic saline prevents this PAF-induced translocation of the p67 oxidase subunit. This finding provides new insight into the mechanisms responsible for osmolar control of PMN functional responses.
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42
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Pinton A, Faraut T, Yerle M, Gruand J, Pellestor F, Ducos A. Comparison of male and female meiotic segregation patterns in translocation heterozygotes: a case study in an animal model (Sus scrofa domestica L.). Hum Reprod 2005; 20:2476-82. [PMID: 15878917 DOI: 10.1093/humrep/dei067] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The comparison of male and female meiotic segregation patterns for individuals carrying identical reciprocal translocations has been rarely reported in mammalian species. The main comparative study involving males and females with comparable genetic background has been performed in the mouse. Swine is another relevant animal model species for meiotic studies. Here we present the segregation patterns determined for sows carrying one of the two following reciprocal translocations: 38, XX, rcp(3;15)(q27;q13), and 38, XX, rcp(12;14)(q13;q21). These segregation data were compared to those previously obtained for closely related boars carrying the same balanced chromosomal rearrangements. METHODS Dual colour in situ hybridization of whole chromosome painting probes was carried out on metaphases of in vitro-matured oocytes II. Segregation results were obtained for 118 and 206 metaphases II respectively for the two translocations. RESULTS Significant differences between sexes were demonstrated for both rearrangements. For instance, for the 3/15 translocation, the chromosomally unbalanced gametes were of different origin: preponderance of the adjacent-I segregation in the male (31.4%), and of the adjacent-II (14.3%) and 3:1 (14.3%) segregations in females. For the 12/14 translocation, the proportion of balanced gametes was greater in males than in females (75.9 and 59.4% respectively). CONCLUSION This study is a new scientific contribution to compare the segregation patterns of male and female carriers of identical chromosomal rearrangements. The results obtained are consistent with those previously reported in mice. Hypotheses to interpret the observed differences between the two translocations, as well as between the male and female segregation patterns, are formulated and discussed.
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43
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Biswas TK, Getz GS. Requirement of different mitochondrial targeting sequences of the yeast mitochondrial transcription factor Mtf1p when synthesized in alternative translation systems. Biochem J 2005; 383:383-91. [PMID: 15257659 PMCID: PMC1134080 DOI: 10.1042/bj20040691] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mitochondrial (mt) translocation of the nuclearly encoded mt transcription factor Mtf1p appears to occur independent of a cleavable presequence, mt receptor, mt membrane potential or ATP [Biswas and Getz (2002) J. Biol. Chem. 277, 45704-45714]. To understand further the import strategy of Mtf1p, we investigated the import of the wild-type and N-terminal-truncated Mtf1p mutants synthesized in two different in vitro translation systems. These Mtf1p derivatives were generated either in the RRL (rabbit reticulocyte lysate) or in the WGE (wheat germ extract) translation system. Under the in vitro import conditions, the RRL-synthesized full-length Mtf1p but not the N-terminal-truncated Mtf1p product was efficiently imported into mitochondria, suggesting that the N-terminal sequence is important for its import. On the other hand, when these Mtf1p products were generated in the WGE system, surprisingly, the N-terminal-truncated products, but not the full-length protein, were effectively translocated into mitochondria. Despite these differences between the translation systems, in both cases, import occurs at a low temperature and has no requirement for a trypsin-sensitive mt receptor, mt membrane potential or ATP hydrolysis. Together, these observations suggest that, in the presence of certain cytoplasmic factors (derived from either RRL or WGE), Mtf1p is capable of using alternative import signals present in different regions of the protein. This appears to be the first example of usage of different targeting sequences for the transport of a single mt protein into the mt matrix.
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Simmons HM, Ruis BL, Kapoor M, Hudacek AW, Conklin KF. Identification of NOM1, a nucleolar, eIF4A binding protein encoded within the chromosome 7q36 breakpoint region targeted in cases of pediatric acute myeloid leukemia. Gene 2005; 347:137-45. [PMID: 15715967 DOI: 10.1016/j.gene.2004.12.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 12/02/2004] [Accepted: 12/15/2004] [Indexed: 11/19/2022]
Abstract
Proteins that contain the recently described MIF4G and/or MA3 domains function in translation, cell growth, proliferation, transformation, and apoptosis. Examples of MIF4G/MA3 containing proteins and their functions include eIF4G, which serves as a scaffold for assembly of factors required for translation initiation, programmed cell death protein 4 (Pdcd4) that inhibits translation and functions as a tumor suppressor, and NMD2, which is essential for nonsense-mediated mRNA decay. MIF4G and MA3 domains serve as binding sites for one or more isoforms of the eIF4A family of ATP-dependent DEAD-box RNA helicases that are required for translation and for nonsense-mediated decay. In this report, we describe the characterization of a novel MIF4G/MA3 family member called NOM1 (nucleolar protein with MIF4G domain 1) that was identified at the chromosome 7q36 breakpoint involved in 7;12 translocations associated with certain acute leukemias of childhood. NOM1, which includes a previously described EST called c7orf3, encodes a ubiquitously expressed transcript composed of 11 exons and an approximately 3 kb 3' UTR that contains several Alu repeats. The predicted NOM1 protein contains one MIF4G domain and one MA3 domain and, consistent with data obtained with other MIF4G/MA3 proteins, interacts with members of the eIF4A family of helicases. Database searches reveal that NOM1 homologs exist in several organisms and that at least two of these are essential genes. Finally, like its Saccharomyces cerevisiae homolog Sgd1p, NOM1 localizes predominantly to the nucleolus. These data demonstrate that NOM1 is a new member of the MIF4G/MA3 family of proteins and suggest that it may provide an essential function in metazoans.
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MESH Headings
- Alu Elements/genetics
- Alu Elements/physiology
- Apoptosis/genetics
- Apoptosis/physiology
- Cell Nucleus/metabolism
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Chromosome Breakage/genetics
- Chromosomes, Human, Pair 7/genetics
- Codon, Nonsense/genetics
- Codon, Nonsense/metabolism
- Eukaryotic Initiation Factor-4A/genetics
- Eukaryotic Initiation Factor-4A/metabolism
- Exons/genetics
- Exons/physiology
- Gene Expression Regulation, Leukemic/genetics
- Gene Expression Regulation, Leukemic/physiology
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Protein Binding/genetics
- Protein Binding/physiology
- RNA Stability/genetics
- RNA Stability/physiology
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Transcription, Genetic/genetics
- Transcription, Genetic/physiology
- Translocation, Genetic/genetics
- Translocation, Genetic/physiology
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Rummel C, Voss T, Matsumura K, Korte S, Gerstberger R, Roth J, Hübschle T. Nuclear STAT3 translocation in guinea pig and rat brain endothelium during systemic challenge with lipopolysaccharide and interleukin-6. J Comp Neurol 2005; 491:1-14. [PMID: 16127698 DOI: 10.1002/cne.20653] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
During systemic inflammation, cytokines are released by immune-competent cells into the circulation, which in turn signal the brain to mediate brain-controlled signs of illness. Cytokine-responsive brain cells can be mapped by histological analysis of cytokine-induced transcription factors or transcription factor-associated molecules revealing different cell phenotypes that respond to activation of the immune system. Critical sites mediating cytokine-dependent immuneffector functions can be divided into two groups, one group of responding cells situated along a tight blood-brain barrier (BBB), and a second cell group in structures with an open BBB, e.g., the sensory circumventricular organs (CVOs). Previous reports from our group suggest that activation of the signal transducer and activator of transcription factor 3 (STAT3) during lipopolysaccharide (LPS)-induced systemic inflammation is mediated by interleukin-6 (IL-6) and occurs in astrocytes of the rat CVOs. Here we show in the guinea pig a time-dependent marked LPS-induced STAT3 activation within astrocytes and endothelial cells of the CVOs, within astrocytes located in brain structures with a functional BBB and within the brain endothelium of the entire brain. In addition, systemic treatment of rats with either rat recombinant IL-6 or LPS induced STAT3 activation in brain endothelial cells in a similar way as observed in the guinea pig brain, stressing the involvement of IL-6 in this phenomenon in a more generalized way. The STAT3-activated brain cells are located in critical target structures mediating cytokine action during LPS-induced inflammation. STAT3-controlled transcriptional activation with yet unknown cell-specific functional consequences seems to be involved in this process.
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47
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Unniraman S, Zhou S, Schatz DG. Identification of an AID-independent pathway for chromosomal translocations between the Igh switch region and Myc. Nat Immunol 2004; 5:1117-23. [PMID: 15489857 DOI: 10.1038/ni1127] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Accepted: 09/22/2004] [Indexed: 11/09/2022]
Abstract
Chromosomal translocations involving immunoglobulin heavy chain (Igh) switch regions and an oncogene such as Myc represent initiating events in the development of many B cell malignancies. These translocations are widely thought to result from aberrant class-switch recombination. To test this model, we measured translocations in mice deficient in activation-induced cytidine deaminase (AID) that lack class-switch recombination. We found that AID made no measurable contribution to the generation of initial translocations, indicating that the intrinsic fragility of the switch regions or a pathway unrelated to AID is responsible for these translocations. In contrast, the outgrowth of translocation-positive cells was dependent on AID, raising the possibility that AID is important in tumor progression, perhaps by virtue of its mutagenic properties.
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48
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Wu CY, Hsieh HL, Jou MJ, Yang CM. Involvement of p42/p44 MAPK, p38 MAPK, JNK and nuclear factor-kappa B in interleukin-1beta-induced matrix metalloproteinase-9 expression in rat brain astrocytes. J Neurochem 2004; 90:1477-88. [PMID: 15341531 DOI: 10.1111/j.1471-4159.2004.02682.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Matrix metalloproteinase (MMP)-9 expression induced by interleukin-1beta (IL-1beta) was investigated in rat brain astrocyte-1 (RBA-1). Here we report that the mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-kappaB) pathways participate in the induction of MMP-9 expression by IL-1beta. Zymographic, western blotting, and RT-PCR analyses showed that IL-1beta increased expression of MMP-9 mRNA and protein, which were inhibited by inhibitors of MEK1/2 (U0126), p38 (SB202190), and JNK (SP600125). In accordance with these findings, IL-1beta stimulated phosphorylation of p42/p44 MAPK, p38, and c-Jun N-terminal kinase (JNK), which was attenuated by U0126, SB202190, or SP600125, respectively. Furthermore, this up-regulation of MMP-9 mRNA and protein was blocked by a specific NF-kappaB inhibitor helenalin. Consistently, IL-1beta-stimulated translocation of NF-kappaB into the nucleus and degradation of inhibitory kappa B-alpha (IkappaB-alpha) was revealed by western blotting and immunofluorescence staining, which was blocked by helenalin, but not by U0126, SB202190, or SP600125. Taken together, these results suggest that in RBA-1 cells, activation of p42/p44 MAPK, p38, JNK and NF-kappaB pathways is essential for IL-1beta-induced MMP-9 gene expression via transcription and translation processes. An increased understanding of the signal transduction pathways involved in IL-1beta-induced MMP-9 expression on RBA-1 may be of potential therapeutic value in the treatment of inflammatory disease.
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Pruneri G, Valentini S, Fabris S, Del Curto B, Laszlo D, Bertolini F, Martinelli G, Leocata P, Viale G, Neri A. Cyclin D3 immunoreactivity in follicular lymphoma is independent of the t(6;14)(p21.1;q32.3) translocation orcyclin D3 gene amplification and is correlated with histologic grade and Ki-67 labeling index. Int J Cancer 2004; 112:71-7. [PMID: 15305377 DOI: 10.1002/ijc.20354] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An abnormal expression of cyclin D3, a key regulator of the cell cycle, has been documented in a variety of human malignancies, and the cyclin D3 gene, mapping to 6p21, may be deregulated in plasma cell myeloma and non-Hodgkin's lymphoma as a result of the t(6;14)(p21.1;q32.3) translocation and/or gene amplification. In the current study, we for the first time investigated by immunohistochemistry and fluorescence in situ hybridization (FISH) the prevalence of cyclin D3 abnormalities in follicular lymphomas (FLs), comparing the results with traditional clinicopathologic characteristics, p27 and skp2 immunoreactivity (IR) and Ki-67 labeling index (LI). Cyclin D3, skp2 and Ki-67 IR significantly increased from grade I to grade III FL (p = 0.0003, p = 0.0001 and p < 0.0001, respectively), while p27 IR was significantly (p < 0.0001) more prevalent in low-grade tumors. Cyclin D3 IR was directly correlated with the Ki-67 LI (p < 0.0001) and inversely correlated with p27 IR (p = 0.050). None of the 13 cases analyzed by FISH showed the t(6;14) translocation, but in 2 (15.3%) grade I FLs 3 cyclin D3 signals were detected. Cohybridization with probes specific for the centromeric region and the long arm of the chromosome 6 indicated trisomy in one case and a pattern highly suggestive for the presence of an isochromosome 6p in the other case. Our data suggest that the t(6;14) translocation may be extremely uncommon in FL and that a deregulated expression of cyclin D3, possibly due to epigenetic mechanisms, may be involved in the pathogenesis of high-grade tumors.
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50
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Kaufer D, Ogle WO, Pincus ZS, Clark KL, Nicholas AC, Dinkel KM, Dumas TC, Ferguson D, Lee AL, Winters MA, Sapolsky RM. Restructuring the neuronal stress response with anti-glucocorticoid gene delivery. Nat Neurosci 2004; 7:947-53. [PMID: 15300253 DOI: 10.1038/nn1296] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Accepted: 07/07/2004] [Indexed: 11/09/2022]
Abstract
Glucocorticoids, the adrenal steroids released during stress, compromise the ability of neurons to survive neurological injury. In contrast, estrogen protects neurons against such injuries. We designed three genetic interventions to manipulate the actions of glucocorticoids, which reduced their deleterious effects in both in vitro and in vivo rat models. The most effective of these interventions created a chimeric receptor combining the ligand-binding domain of the glucocorticoid receptor and the DNA-binding domain of the estrogen receptor. Expression of this chimeric receptor reduced hippocampal lesion size after neurological damage by 63% and reversed the outcome of the stress response by rendering glucocorticoids protective rather than destructive. Our findings elucidate three principal steps in the neuronal stress-response pathway, all of which are amenable to therapeutic intervention.
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MESH Headings
- 11-beta-Hydroxysteroid Dehydrogenase Type 2/genetics
- 11-beta-Hydroxysteroid Dehydrogenase Type 2/metabolism
- Animals
- Blotting, Western/methods
- Cell Count/methods
- Cell Death/drug effects
- Cell Death/genetics
- Culture Techniques
- Estrogen Receptor alpha
- Fibroblast Growth Factors/genetics
- Fibroblast Growth Factors/metabolism
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Glucocorticoids/antagonists & inhibitors
- Hippocampus/drug effects
- Hippocampus/physiology
- Humans
- Immediate-Early Proteins
- Immunohistochemistry/methods
- Indoles
- Kainic Acid/toxicity
- Male
- Microtubule-Associated Proteins/metabolism
- Models, Molecular
- Neurons/drug effects
- Neurons/physiology
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Protein Structure, Tertiary/physiology
- RNA, Messenger/metabolism
- Rats
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
- Recombinant Fusion Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Stress, Physiological/genetics
- Stress, Physiological/metabolism
- Transgenes
- Translocation, Genetic/physiology
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